Cellular communications systems have varying capacities. Some areas served by fixed cellular services have limited coverage. Others are not served by fixed cellular services at all. Typically, when more capacity is desired in areas with existing coverage, existing cell sites are divided into a larger number of sectors. The additional sectors can reuse resources such as frequency channels, but they are limited geographically to areas surrounding existing cell sites. When demand increases at a distance from existing cell sites, additional cell sites can be installed. These approaches to increasing capacity take time, in part because equipment needs to be added, and additional cell sites may need to be secured and towers may need to be built.
Cell sites and sectors can also be modified to evenly distribute the call load between them. This may be desirable when different cell sites and sectors within cell sites experience different loading. For example, two adjacent cell sites may have widely varying call loads based on their relative location. If one is closer to a densely populated area or freeway, it may experience a higher volume of calls. High call loads on a cell or a sector of a cell can be relieved by adding an additional cell, or by dividing an existing cell into a greater number of sectors. Both of these techniques typically require additional equipment and installation time.
Accordingly, a significant need exists for methods and apparatus for providing cellular services a distance away from existing cell sites, and for modifying and distributing loading between different communications resources.